Table 2.

Age distribution and risk categories

	children			working adults		elderly
	0–5	6–12	13–19	20–39	40–59	60 +
Population size Na	5,272	6,773	7,952	25,959	29,127	24,917

A population of N = 100,000 inhabitants of Germany is subdivided according to age a and risk category r. We assume that all age groups are fully susceptible at begin of the outbreak. A fraction of F_a = 6% of all children (age < 20 years) are regarded as being under high risk (r = r₁) after an influenza infection whereby the remaining 94% are under low risk (r = r₂). The high risk fractions of working adults (ages 20–59) and elderly (ages 60+) are F_a = 14% and F_a = 47%, respectively. Source: [9]